<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<form action="/update">
    <input type = "hidden" name="id" th:value="${user.id}">
    用户名:<input type = "text" name="username" th:value="${user.username}"/><br/>
    密码:<input type = "text" name="password" th:value="${user.password}"/>
    <input type="submit" value="修改">
</form>
</body>
</html>